Not really. A startup's need is always revolving around what the founders can pull off- how creative and how shameless you are.
Lets think outside the box here:
If you absolutely have to market during a break, follow your potential users. Showcase at events, attent clubs, the beach, go to the destinations even in Mexico where a lot go to and ghand out download cards with codes.
Go to hiking places and leave then in their cars so they find them on their way home.
Go the places where the app would bring more value to them if they downloaded in that moment.
You need to find and understand the behavior of your target audience ie. college students during the summer months.
I'd start with the most concrete thing, summer internships and take it from there.
Your goal before the summer should be to completely understand the audience. Where do they go? what do they do? what do they pay attention to?
Once you've done the leg work and analyzed their behavior start formulating some plans as to how to reach them.
You should brainstorm several ideas and keying in on the ones you believe will be most effective. I'd select 2-3 you believe will be your best performing and execute.
Be sure to track the data and determine which method has been most successful for you.
Paid advertising is the only day if you do nothing now and start your actual campaign on summer.
If you start from tomorrow the best way to market your app are
1. Define the challenges and goals of your buyer personas
2. Create the buyer journey how they find the app, what are the next steps after they download, how you delight them and make them your app promoters
3. Create your inbound strategy and what kind of content would you need to help them to make their decision faster and support them in their stages of buyer journey (FAQ pages, best practices, tips, gifs, short explainer vidoes and so on)
4. Prepare your journalist outreach campaigns and your pitches. I recommend doing some A/B testing on your subject lines and email content before reaching to bigger ones
Kindly let me know if you have any questions!